The invention relates to the conferencing of users of a local or wide area network (LAN/WAN). Specifically, the method and system of the present invention provide for synthetic stereo audio conferencing of a plurality of users over a LAN/WAN.
Allowing multiple telephone users to be connected to and communicate with one another on the same call, a feature known as xe2x80x9cconferencing,xe2x80x9d is a commonly found and popular application of traditional circuit-switched telephone networks. Since conference calls involve a number of parties, from the perspective of an individual user involved in such a call, it is often desirable to be able to discern which one or more of the parties are talking at any given time. For a variety of reasons, it can sometimes be difficult to distinguish between talkers in a conference call. For example, they may have similarly sounding voices, they may be talking at the same time or they may be speaking too softly to distinguish; between them.
One way to provide the users involved in a conference call with some idea as to which of the other parties in the call is talking is to provide for stereo signal transmission and to equip the users with stereo speakers. For example, in the case where one of the parties of a conference call is actually a small room full of people, multiple microphones may be used. The distribution of a talker""s signal between the microphones tends to differentiate the various talkers within the room. If a left and a right microphone are used and the signals generated therefrom can be transmitted to the others users, those other users with stereo speakers (left and right) will be able to distinguish between talkers in the room based upon the left to right distribution of the talkers"" voices. In other words, the voice of a talker in the left side of the room will, to the receiving users in the conference call, sound xe2x80x9clouderxe2x80x9d in the left speaker of the user equipment than in the right. Thus, that particular talker will sound, to the other users, as though the talker were located on the left in relation to other talkers in the room. The remaining users involved in the conference call will be able to distinguish between talkers in the room based upon their xe2x80x9clocationxe2x80x9d relative to each other. Such a method, however, has limited application in that it requires that spatially distributed microphones receive the talkers"" signals. Furthermore, the method does nothing to help the user differentiate between the parties in other locations who may also be involved in the conference call.
Having identified the above-described problems, the inventors have developed the following solution, which is embodied in the present invention. As described herein, the present invention provides a method of and system for facilitating synthetic stereo audio conferencing of a plurality of users over a local or wide area network (LAN/WAN). The disclosure describes a system architecture using a LAN/WAN to support synthetic audio conferencing thus allowing, at a receiving user location, for the spatially distinct xe2x80x9cplacementxe2x80x9d of the other parties involved in a conference call. This enables the user to differentiate between the various other parties and to discern which one or more of the parties are talking at any given time. Under the present invention, individual parties need not be in the same room or have stereo microphones.
In one embodiment of the present invention for providing synthetic stereo audio conferencing of a plurality of clients over a local or wide area network (LAN/WAN), one of the clients receives the transmitted signals from each of the other clients over the LAN/WAN. Stereo versions of each of the received signals are synthesized then mixed at the one client to create a composite signal distributed over stereo channels to effect virtual positioning of each of the other clients. The composite signal is then output to the user of the one client as stereo audio over, for example, a left speaker and a right speaker, such that the other conferenced parties sound as though they are spatially distributed about the user.
In another embodiment of the present invention for providing synthetic stereo audio conferencing of a plurality of clients over a local or wide area network (LAN/WAN), a server within the LAN/WAN receives the transmitted signals from the plurality of clients. Stereo versions of each of the received signals are synthesized and then mixed at the server to create at least one client-specific composite signal distributed over multiple channels to effect virtual positioning of the plurality of clients. This composite signal is then transmitted to one of the clients. The client-specific composite signal transmitted to that one client does not include that client""s own transmitted signal (which would otherwise be received as echo). The composite signal is then output to the user of the one client as stereo audio over, for example, a left speaker and a right speaker, such that the other conferenced parties sound as though they are spatially distributed about the user.
In yet another embodiment of the present invention for providing synthetic stereo audio conferencing of a plurality of clients over a local or wide area network (LAN/WAN), a server within the LAN/WAN receives the output signals from the plurality of clients. Stereo versions of the received signals are synthesized and then mixed at the server to create a single multicast signal distributed over multiple channels to effect virtual positioning of the clients. The multicast signal is transmitted to each of the clients. A client receiving the multicast signal comprises an echo controller for removing, from the received multicast signal, a synthetic stereo component corresponding to the signal transmitted from that client. The remaining, composite signal is output to the user of the client as stereo audio over, for example, a left speaker and a right speaker, such that the other conferenced parties sound as though they are spatially distributed about the user.
Other features and advantages of the present invention will become apparent to those skilled in the art from the following detailed description. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the present invention, are given by way of illustration and not limitation. Many changes and modifications within the scope of the present invention may be made without departing from the spirit thereof, and the invention includes all such modifications.